A clinical investigation was undertaken on primary male infertility patients of recent 5 years. The results obtained were as follow: 1. Suspective etiologic factors were: 1) testicular failure, 36.1 %; 2) varicocele, 18.7%; 3) endocrine abnormality, 13.5%; 4) obstruction, 13.5%; 5) idiopathic, 10.9%; 6) cryptorchidism, 2.6%; 7) necrospermia, 0.9%. 2. On semen analyses, azoospermia was found in 55.8%, single abnormal parameter in 21.5 %, and multiple/all abnormal parameter in 22.7% of the 163 cases. 3. For the evaluation of the sensitivity and specificity of noninvasive variables in predict in obstruction as the cause of azoospermia in patient who had undergone testicular biopsy, the testicular size and serum follicle-stimulating hormone(FSH) level revealed 100% of sensitivity. 4. Among the 43 patients with a testicular biopsy confirmed diagnosis there was a significant difference in testicular size, ejaculate volume(p<0.0001) and serum FSH(p<0.0001) between patients with testicular failure and those with ductal obstruction. 5. Of 93 treated patients with primary male infertility, 42 were managed by medical treatment including endocrine treament, retrograde ejaculation treatment, infection treatment and observation; 29 were managed by surgical treatment including varicocelectomy, vasovasostomy, vasoepididymostomy and TUR of ejaculatory duct; 20 were managed by sperm preparation treatment including artificial insemination(AI), electroejaculation plus AI and vibration ejaculation plus AI ; 2 were managed by microscopic epididymal sperm aspiration plus IVF, repectively. 6. 42 patients who could be followed-up, 21 patients(50%) impregnated their wives.